In order to solve the problem it is proposed in U.S. 2010/0077984 A1 to support both crankshafts in a joint support block in order to eliminate the clearance between the tooth flanks and to select the material for the support block and the material for the crankshafts and the material for the synchronization gears with respect to its thermal expansion coefficient, so that the thermal expansion of the support block between the two rotation axes of the crankshafts is substantially identical with the thermal expansion of the synchronization gears. This however causes a configuration with substantial complexity.
An adjustable support block for a twin crankshaft piston engine is known from DE 10 2006 060 660 A1, wherein the offset between the axes of the crankshafts is configured adjustable, so that an undesirable support clearance and tooth flank clearance can be eliminated in this manner. Also this solution is rather complex with respect to its technical implementation.
It is known from DE 10 2006 036 827 A1 to provide a piston with a convex external contour for a twin crankshaft piston engine. The piston tolerates a minor tilting of the longitudinal piston axis relative to the longitudinal cylinder axis caused by an asymmetry of the rotation of the crankshafts without causing a binding of the piston in the cylinder or increased friction.